Derivatives (Embedded Derivatives) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 1,766	$ 3,537
Embedded Derivative, Fair Value of Embedded Derivative Liability	(606)	1,261
Ceded Guaranteed Minimum Benefit [Member] | Premiums, reinsurance and other receivables [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	1,797	3,551
Direct Guaranteed Minimum Benefit [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	(674)	705
Assumed Guaranteed Minimum Benefit [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	(7)	4
Funds withheld on ceded reinsurance [Member] | Other liabilities [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	75	552
Options embedded in debt or equity securities [Member] | Investments [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ (31)	$ (14)